Automatic test equipment (ATE) refers to an automated, usually computer-driven, system for testing devices, such as semiconductors, electronic circuits, and printed circuit board assemblies. A device tested by ATE is referred to as a device under test (DUT).
ATE typically includes a computer system and a testing device or a single device having corresponding functionality. ATE is capable of providing signals to a DUT via its source channels. Capture channels receive signals from the DUT and forward those signals for processing to determine whether the DUT meets testing qualifications.
Harmonic distortion significantly limits the dynamic range of current generation ATE instrumentation. Audio, video, communications, and wireless systems are all sensitive to harmonic distortion, as is manifest in stringent total harmonic distortion (THD), spurious free dynamic range (SFDR), and adjacent channel power ratio (ACPR) specifications on devices for those markets. Across the frequency spectrum, from audio to very high frequency (VHF), instrument harmonic levels are typically more than 10 decibels (dB) higher than non-harmonic spurious signals. ATE users often determine that production tests of device AC (alternating current) linearity are limited by capabilities of their ATE instrumentation, particularly the harmonic distortion.